Biologic instability of pancreatic cancer xenografts in the nude mouse.

Tumor transplants into nude mice (NM) may reveal abnormal biological behavior compared with the original tumor. Despite this, human tumor xenografts in NM have been widely used to study the biology of tumors and to establish diagnostic and therapeutic modalities. Clearly, precise differences in the biology of a given tumor in human and in NM cannot be assessed. We compared the growth kinetics, differentiation pattern and karyotype of an anaplastic Syrian hamster pancreatic cancer cell line in NM and in allogenic hamsters. As with the original tumor, transplants in hamsters grew fast, were anaplastic and expressed markers related to tumor malignancy like galectin 3, TGF-alpha and its receptor EGFR at high levels. However, tumors in the NM were well-differentiated adenocarcinomas, grew slower, had increased apoptotic rate and had a high expression of differentiation markers such as blood group A antigen, DU-PAN-2, carbonic anhydrase II, TGF-beta(2) and mucin. Karyotypically, the tumors in the NM acquired additional chromosomal damage. Our results demonstrate significant differences in the morphology and biology of tumors grown in NM and the allogenic host, and call for caution in extrapolating data obtained from xenografts to primary cancer.

Control of metastasis by Asn-linked, beta1-6 branched oligosaccharides in mouse mammary cancer cells.

Studies in cell lines and malignant human tissues have shown that increased cell-surface Asn-linked beta1-6(GlcNAcbeta1-6Man) branching is associated with increased tumorigenic and metastatic properties. In this study, three mouse mammary cancer cell lines were transfected with an expression vector containing the mouse cDNA for N-acetylglucosaminyltransferase V (GlcNAcT-V EC 2.4.1.155), the glycosyltransferase responsible for initiating beta1-6 branching on Asn-linked carbohydrates. The cell lines were screened for increased cytotoxicity to L-PHA, a lectin specific for beta1-6 branching structures. Cell lines exhibiting increased L-PHA cytotoxicity expressed increased levels of beta1-6 branching structures. Northern blots detected the presence of GlcNAcT-V transcribed from the expression vector in the L-PHA sensitive cell lines. After injection into the tail veins of mice, transfected cell lines with increased beta1-6 branching on the cell surface formed elevated levels of lung tumors relative to control transfected cell lines (P < 0.002). Western blots of membrane proteins from GlcNAcT-V transfected and control cells probed with the lectins DSA and WGA did not show an increase in polyN-acetyllactosamine and sialic acid content in the transfected cell lines. These results demonstrate that a specific increase in beta1-6 branching due to an elevation in GlcNAcT-V expression increases metastatic potential.

N-linked oligosaccharides and metastatic propensity in in vivo selected mouse mammary adenocarcinoma cells.

Studies using metastatic variant selected in vivo from a cloned parental cell line demonstrate that the expression of beta1-6 branched, N-linked carbohydrates and sialic acid were positively associated with in vitro invasiveness and inversely associated with metastatic potential, adherence, and in vivo growth rate. These results suggest that at least within one tumor model, a negative association occurs between metastatic potential and 1-6 branched oligosaccharide expression. In these studies two metastatic variants, Cl-66M1 and Cl-66M2, were selected following serial in vivo passage of Cl-66, a clonal cell line obtained from a mouse mammary adenocarcinoma cell line. The parent cell line and the two metastatic variants were approximately equal in their adherence to fibronectin, laminin, and collagen type IV coated plastic. In contrast, both Cl-66M1 and Cl-66M2 had a significantly increased ability to invade through matrigel invasion chambers and expressed significantly increased levels of beta1-6 branched, N-linked carbohydrates, and sialic acid compared to the clonal parental cell line, Cl-66. Furthermore, the in vivo tumor growth rates of these selected variants were decreased compared to Cl-66 with the longest tumor volume doubling time observed with Cl-66M2.

Localization of galectin-3 in normal and diseased pancreatic tissue.

CONCLUSION: Galectin-3 is expressed in both human and hamster pancreatic tumors and tumor cell lines and this expression is increased over normal. BACKGROUND: Galectin-3 is overexpressed in many gastrointestinal tumors. This study examined the expression of galectin-3 in human and hamster pancreatic tumors to determine if galectin-3 could be used as a marker for pancreatic cancer. METHODS: Membranes were prepared from human and hamster pancreatic tumor cell lines. Galectin-3 was visualized by immunoblot analysis of separated membrane proteins using the monoclonal antibody (MAb) M3/38. Paraffin-embedded sections from normal, pancreatitis, and cancerous human pancreatic tissue and normal, N-nitrosobis(2-oxopropyl)amine (BOP)-treated hyperplastic, and cancerous hamster pancreatic tissues were processed immunohistochemically for galectin-3 using the MAb M3/38. RESULTS: Galectin-3 was heavily expressed in cytoplasmic and nuclear regions of 50% of normal human pancreatic tissue. Expression of galectin-3 in ductal cells in chronic pancreatitis and cancerous pancreatic tissue was increased over normal and was more uniform (>95% cells/duct stained). Normal hamster pancreatic ducts showed weak or no expression of galectin-3. Hyperplastic pancreatic ductal cells from BOP-treated hamsters heavily expressed galectin-3 (60-95% cells/duct stained). Galectin-3 expression in ductal cells in cancerous pancreatic lesions was increased to >95%. Galectin-3 was also detected in the pancreatic nerves in all human tissue specimens tested.

Modification of blood group A expression in human pancreatic tumor cell lines by inhibitors of N-glycan processing.

Pancreatic adenocarcinomas induced in Syrian hamsters by N-nitrosobis (2-oxopropyl)amine (BOP) treatment express blood group A (BGA) antigen, which was previously shown by this lab to be expressed on multiantennary asparagine (Asn)-linked glycans attached to membrane glycoproteins. To determine if a similar expression pattern was found in humans, three human pancreatic ductal adenocarcinoma cell lines (CD18, CD11, and Capan 1) from individuals of blood type A were analyzed and shown to express BGA antigen on membrane glycoproteins similar in molecular mass to those found in hamster tumor cells. The BGA antigen was located on Asn-linked oligosaccharides in all three human cell lines, as indicated by loss of activity after peptide:N-glycosidase F (PNGase F) treatment. Also, as shown previously in hamster pancreatic tumor cells, BGA expression at the surface of the human cell lines was blocked by growth of the cells in media containing deoxymannojirimycin (dMM), an inhibitor of mannosidase I. These results demonstrate that the BGA antigen is on Asn-linked glycans in human pancreatic adenocarcinoma cells and that these glycoproteins are processed similarly to the BGA glycoproteins in hamster pancreatic adenocarcinoma.

A novel adhesion factor produced by hamster pancreatic cancer cell line is effective on normal and carcinoma cell lines of different species.

An adhesion factor, produced by the hamster pancreatic cancer cell line PC-1.0, was tested for its efficiency in promoting the in vitro adhesion of normal and tumor cells (pancreas, lung, kidney, colon, breast, skin, prostate, neuroblast, melanocyte) derived from human, monkey, bovine, hamster, and rat sources. Using a modification of the dimethylthyazol diphenyl tetrazolium (MTT) assay, the factor was found to induce adhesion in all cell lines in a dose-dependent manner. Although the effect was variously expressed, there was a statistically significant difference between the MTT absorbance of cells incubated in the presence or absence of the factor. Conditioned medium of each cell line tested showed significantly less adhesion effect than that produced by PC-1.0 cells. Because our previous study indicated that the adhesion factor produced by PC-1.0 cells differed from known growth factors and adhesion molecules including fibronectin, vibronectin, laminin, and collagen, it appears that PC-1.0 cells produce a novel adhesion factor that enhances adherence of normal and malignant cells of different species.

Dietary energy restriction-induced modulation of protein kinase C zeta isozyme in the hamster pancreas.

Dietary restriction in experimental animals enhances life span, delays disease, inhibits immunological perturbations, and ameliorates cancer. Protein kinase C (PKC) isozymes mediate signals generated by hormones, growth factors, and neurotransmitters for cell proliferation and differentiation. The results of our study showed that a C-terminally directed anti-PKC zeta antibody detected an 81-kDa band in the pancreases of control and energy-restricted hamsters. Syrian golden hamsters were fed energy-restricted diets formulated such that the hamsters received 90% (10% energy restriction (ER)), 80% (20% ER), or 60% (40% ER) of the total energy consumed by control hamsters, with the energy reduced proportionally from fat and carbohydrate. ER decreased PKC zeta isozyme levels by 40-75% in hamsters fed 10, 20, and 40% ER diets for 8 wk. PKC zeta isozyme expression was decreased by 75-80% in hamsters fed ER diets for 15 wk. Although ER caused significant decreases in PKC zeta isozyme levels compared with those of control hamsters at both time points, the relative differences in PKC zeta levels between the dietary ER groups (10, 20, and 40%) were small and not significant. A significant decrease in the body weights of ER animals compared with those of controls was observed at both time points. No differences in tomato lectin and phytohemagglutinin reactivity were observed between control animals and animals fed 10, 20, and 40% ER diets. Furthermore, the cellular expression of PKC zeta in the hamster pancreas did not differ among hamsters fed the various ER diets. These observations may be important for understanding not only the role of dietary ER in pancreatic cancers but also PKC zeta signal transduction mechanisms in normal pancreatic physiology.

Protein glycosylation and myristylation in Chlorella virus PBCV-1 and its antigenic variants.

Chlorella virus PBCV-1 particles contain three glycoproteins, the major capsid protein Vp54 and two minor proteins Vp280 and Vp260. The major capsid protein is myristylated as well as glycosylated. Both modifications are in the carboxyl-terminal portion of the protein. A gene which is modified in a PBCV-1 antiserum-resistant mutant was cloned and sequenced. This gene has an open reading frame of 3099 bases and encodes one of the two large virion glycoproteins (Vp260). Vp260 contains 13 tandem repeats of 61 to 65 amino acids. The mutation deletes the equivalent of four of the amino acid repeat sequences and duplicates one of these sequences.

Tumor cell surface beta 1-6 branched oligosaccharides and lung metastasis.

NIH3T3 cells transfected with an activated Ha-ras oncogene were treated with L-PHA, the leukoagglutinin from red kidney beans. Cell lines resistant to L-PHA-mediated cytotoxicity were isolated and found to contain reduced levels of L-PHA-binding oligosaccharides. The levels of N-acetylglucosaminyltransferase V, the enzyme responsible for the initiation of the beta 1-6 branch, were reduced in L-PHA-resistant cells. Tumorigenicity in nude mice was unchanged by the change in oligosaccharide expression, but the ability to form lung tumors after intravenous injection was significantly reduced. These results demonstrate that the ability of NIH3T3 cells transfected with an activated Ha-ras oncogene to form lung tumors after intravenous injection into nude mice is reduced in all six L-PHA selected cell lines containing a reduction in beta 1-6 branched Asn-linked oligosaccharides.

Comparison of p53 protein expression and cellular localization in human and hamster pancreatic cancer cell lines.

We compared the expression of p53 protein in four human pancreatic cancer cell lines (HPAF, CD11, CD18 and PANC-1) and four hamster pancreatic cancer cell lines (PC-1, PC-1.2, PC-1.0 and H2T) by the monoclonal antibodies PAb421 and PAb240. PAb421 reacted with all human pancreatic cancer cell lines but not with the hamster cells. PAb240, on the other hand, reacted with all human and hamster pancreatic cancer cell lines in immunoblotting and in immunocytochemistry. However, immunoprecipitation with PAb240 was detected only in human cell lines HPAF, CD11 and CD18 cells but not in PANC-1 or in any of the hamster cell lines. During exponential growth, immunoreactivity was detected mainly in the nucleus of PC-1, PC-1.2 and PANC-1 cells (nuclear type) and in both the nucleus and the cytoplasm of PC-1.0, H2T, HPAF, CD11 and CD18 cells (diffuse type). At the confluence, the expression of p53 was decreased in most of the human cell lines as was proliferative cell nuclear antigen. After incubation with 1 mM hydroxyurea, cells with nuclear p53 expression did not show an altered cellular distribution of p53 protein, whereas cells with a diffuse type of localization pattern showed an increase in the nuclear staining. On the other hand, cytoplasmic immunoreactivity was found in PC-1.0, PC-1, PC-1.2, HPAF, CD11 and CD18 cells that were treated with 100 ng/ml of nocodazole. After heat stress with 1 h incubation at 42 degrees C, p53 protein was detected in the cytoplasm and nucleolus of all cell lines. After 24-48 h incubation at 37 degrees C, this change in cellular distribution of p53 in response to heat stress was reverted to a preheat stress pattern. The overall results suggest that neither the p53 of PANC-1 nor the hamster pancreatic cancer cell lines are immunoprecipitated with the PAb240. It appears that cell cycle and heat stress are two of the factors that influence cellular localization of p53 protein in both human and hamster pancreatic cancer cells.

UDP-GalNAc:Fuc alpha 1-2Gal alpha 1-3GalNAc transferase activity in hamster pancreatic cancers and in normal hamster alimentary tissues.

Ductal adenocarcinomas induced by N-nitrosobis(2-oxopropyl)amine treatment in Syrian hamsters produce blood group-A antigen, which is not present in normal hamster pancreas. To understand the underlying mechanism of A antigen neoexpression in pancreatic cancer cells, we examined the activity of UDP-GalNAc:Fuc alpha 1-2Gal alpha 1-3GalNAc transferase (A-transferase), the enzyme responsible for blood group-A antigen production. The specific activity of A-transferase in the pancreatic cancers was approximately 8 nmol/mg protein/h in membrane preparations, 0.3 nmol/mg protein/h in whole cell extracts, and undetectable in normal hamster pancreas. Significant A-transferase activity was found in normal tissues expressing blood group-A antigen. Although both normal (gastric antrum, colon) and pancreatic cancer cells showed similar enzymatic characteristics (optimal pH, substrate affinity, optimal [Mn2+]), there was a difference in the requirement for divalent cations. The A-transferase in cancer cells showed a more stringent requirement for Mn2+. These results suggest that A-transferase is activated during nitrosamine-induced pancreatic carcinogenesis, which results in the neoexpression of blood group-A antigen. The difference in divalent cation requirements between A-transferase activities of cancer and normal cells may indicate that there are multiple A-transferases present in hamster tissues.

Glycan structure of blood group-A antigen in hamster normal tissues and pancreatic cancers.

Pancreatic cancers induced by N-nitrosobis(2-oxopropyl)amine in Syrian hamsters produce blood group A antigen. The glycan structure of the blood group A antigen-bearing glycoproteins purified from pancreatic cancer cells has been shown previously to be bound to Asn-linked complex oligosaccharides. Because blood group A antigen has usually been described as being on Ser/Thr-linked glycans, the distribution and glycan-protein linkage of the antigen were examined in normal hamster tissues in comparison with the findings on pancreatic cancer cells. The gastrointestinal tract, excluding the small intestine, expressed blood group A antigen. The liver, pancreas, and gallbladder did not show blood group A reactivity. Blood group A antigen in the proximal gastrointestinal tract was resistant to peptide N-glycosidase F digestion, which cleaves Asn-linked glycans from core proteins. Blood group A antigen was peptide N-glycosidase F sensitive in membrane preparations from pancreatic cancers. In the colon, this antigen was only partially removed by peptide-N-glycosidase F. These results demonstrate a difference in the structure of blood group A antigen-associated glycan between pancreatic cancers and normal hamster gastrointestinal tissues.

Evidence for virus-encoded glycosylation specificity.

Four spontaneously derived serologically distinct classes of mutants of the Paramecium bursaria chlorella virus (PBCV-1) were isolated using polyclonal antiserum prepared against either intact PBCV-1 or PBCV-1-derived serotypes. The oligosaccharide(s) of the viral major capsid protein and two minor glycoproteins determined virus serological specificity. Normally, viral glycoproteins arise from host-specific glycosylation of viral proteins; the glycan portion can be altered only by growing the virus on another host or by mutations in glycosylation sites of the viral protein. Neither mechanism explains the changes in the glycan(s) of the PBCV-1 major capsid protein because all of the viruses were grown in the same host alga and the predicted amino acid sequence of the major capsid protein was identical in the PBCV-1 serotypes. PBCV-1 antiserum resistance is best explained by viral mutations that block specific steps in glycosylation, possibly by inactivating glycosyltransferases.

Production of scatter factor-like activity by a nitrosamine-induced pancreatic cancer cell line.

Two hamster pancreatic cancer cell lines, PC-1 and PC1.0, established from N-nitrosobis(2-oxopropyl)amine-induced pancreatic ductal/ductular adenocarcinomas exhibit different growth patterns. PC-1 cells, which produce well differentiated adenocarcinomas in vitro after allogeneic inoculation, form cell aggregates and characteristic island-like structures in vitro. PC1.0 cells, which produce poorly differentiated tumors in vivo, form dispersed colonies in vitro. Conditioned medium prepared from PC1.0 cells inhibits PC-1 cells from forming island-like colonies. The conditioned medium also prevents several human pancreatic carcinoma cell lines, HPAF, CD11 and CD18, from forming compact colonies. These properties are similar to those described previously as scatter factors. The scatter factor-like activity is heat-labile, acid-stable, non-dialyzable, trypsin sensitive and unaffected by reducing agents. The activity is not suppressed by addition of heparin, and it does not bind to heparin. In addition, the scatter phenomenon is not reproduced by acidic or basic fibroblast growth factor, epidermal growth factor or transforming growth factor-beta 1. Based on these findings, it appears that the scattering activity produced by PC1.0 cells differs from the scatter factors that have been identified in other systems.

Relationship between blood group-A antigen expression and malignant potential in hamster pancreatic cancers.

The loss of expression of the ABH blood group antigens is suggested to be associated with more aggressive behavior of cancers. We have compared the growth behaviors of two hamster pancreatic cancer cell lines with different blood group-A expressions. PC-1.0 cells, which expressed blood group-A antigen poorly, showed a faster growth in vitro and in vivo when implanted into the pancreas of homologous animals, whereas PC-1.2 cells, all of which express the antigen, had a slower growth rate both in vitro and in vivo. PC-1.0 also tended to metastasize, whereas PC-1.2 cells grew primarily locally. The allografts of both PC-1.2 cells (PC-1.2AG) and PC-1.0 cells (PC-1.0AG) and the metastases of PC-1.0 cells expressed blood group A antigen in a similar rate. There was no significant difference in the number of A-antigen positive cells (A+) between the PC-1.2AG and PC-1.0AG, although the expression of A antigen in PC-1.0AG showed a greater heterogeneity. The combined immunohistochemistry and autoradiography did not show any significant differences in the labeling index of A+ or A- cells between the two allografts. Thus, the results indicate that blood group A antigen expression is unrelated to malignancy in this model. The faster growth rate of PC-1.0 cells may be due to their shorter cell cycle.

Purification and analysis of glycoproteins bearing blood group-A determinants from hamster pancreatic ductal adenocarcinomas.

Although the hamster pancreas does not express A, B or H blood group antigens, all hamster pancreatic ductal adenocarcinomas induced by treatment with N-nitrosobis(2-oxopropyl)amine express blood group-A antigen. Thus, the acquisition of blood group-A antigen expression in this system is a cancer-associated alteration. We have purified three major blood group-A antigen bearing glycoproteins (gp120, gp135 and gp150) from hamster pancreatic cancer cell membrane preparations using affinity chromatography on DBA (Dolichos biflorus) agglutinin-agarose. When assayed by immunoblotting, gp120 and gp135 showed strong blood group-A reactivity, which was removed by treating membrane samples with peptide-N-glycosidase F. Blood group-A reactivity was unchanged by treatment of the membrane fractions with endoglycosidases F and H. In addition, these two glycoproteins bearing blood group-A antigen also bound L-PHA (Phaseolus vulgaris leucoagglutinin). These results demonstrate that gp120 and gp135 express blood group-A antigen on Asn-linked multi-antennary complex type glycan structures. The gp150 showed weak blood group-A expression. This is the first demonstration of the neoexpression of cancer-associated blood group-A determinants which reside on Asn-linked glycan structures.

Modification of blood group A antigen expression in a pancreatic cancer cell line (PC-1) by inhibitors of N-glycan processing.

Pancreatic adenocarcinomas induced in Syrian hamsters by treatment with N-nitrosobis(2-oxopropyl) amine express blood group A antigen, which is absent in normal pancreatic cells. On membrane glycoproteins purified from tumors, blood group A antigen has been found to be expressed on multiantennary Asn-linked complex glycans. In this study, we investigated the effect of inhibitors of Asn-glycan processing on blood group A antigen bearing glycan structures in a cell line (PC-1) established from a primary induced pancreatic cancer. Expression of blood group A antigen on cells and in membrane preparations was blocked by treatment with 1-deoxymannojirimycin, an inhibitor of mannosidase I, but was retained after treatment with swainsonine, an inhibitor of mannosidase II. However, swainsonine treatment altered the glycan structure associated with blood group A antigen from an endoglycosidase H resistant type to a sensitive type, indicating that the blood group A structure might shift from a complex type to a hybrid type glycan by this treatment. These results demonstrate that Asn-linked glycans carry the major blood group A antigens in PC-1 cells.

The protein-tyrosine kinase substrate, calpactin I heavy chain (p36), is part of the primer recognition protein complex that interacts with DNA polymerase alpha.

Primer recognition proteins (PRP) stimulate the activity of DNA polymerase alpha on DNA substrates with long single-stranded template containing few primers. Purified PRP from HeLa cells and human placenta are composed of two subunits of 36,000 (PRP 1) and 41,000 (PRP 2) daltons. By amino acid sequence homology, we have identified PRP 2 as the glycolytic enzyme 3-phosphoglycerate kinase. Here we present data that establishes PRP 1 to be the protein-tyrosine kinase substrate, calpactin I heavy chain. Amino acid sequence analysis of six tryptic peptides of PRP 1 followed by homology search in a protein sequence data base revealed 100% identity of all six peptides with the deduced amino acid sequence of human calpactin I heavy chain. The activities of PRP and calpactin I coelute on gel filtration columns, and a high correlation of PRP and calpactin I activities was seen at different stages of purification. A rabbit polyclonal anti-chicken calpactin I antibody was shown to cross-react with PRP 1 polypeptide at various stages of PRP purification, and the homogeneous preparation of PRP exhibits 3-phosphoglycerate kinase (PRP 2) and calpactin I (PRP 1) activities. PRP activity is neutralized by a mouse monoclonal anti-calpactin II antibody although having no effect on the polymerase alpha activity itself. Calpactin II has a 50% amino acid sequence homology with calpactin I. However, PRP 1 is not calpactin II as shown by lack of cross-reaction to a monoclonal anti-calpactin II antibody on Western blots. Calpactin I and 3-phosphoglycerate kinase, purified independently, cannot be efficiently reconstituted into the PRP complex, indicating that their association in the PRP complex involves specific protein-protein interactions that remain to be elucidated. The biochemical and immunological data presented here revealing the identity of PRP 1 as calpactin I provide evidence for one physiological role of calpactin I in the cell.

Subcellular localization of blood group A substance produced by pancreatic adenocarcinoma induced in hamsters by N-nitrosobis(2-oxopropyl)amine (BOP) and by its cell line (PC-1).

The subcellular localization and biochemical characteristics of blood group A antigen were studied by immunogold methods and by SDS-PAGE and Western blotting procedures in N-nitrosobis)2-oxopropyl)amine (BOP)-induced pancreatic cancer (PC) in Syrian hamsters, in the pancreatic cancer cell line (PC-1) derived from a primary induced pancreatic cancer, and in intrapancreatic and subcutaneous transplants of PC-1 cells. Normal hamster duodenal epithelial cells expressing A antigen were compared with the normal hamster pancreas (lacking A antigen), human PC tissues from patients with blood group A and human PC cell lines. Blood group A antigen was present on the membrane of hamster duodenal cells, but was absent in the normal pancreatic cells. A antigen was localized mainly on the cell membrane of the hamster cancer cells both in vivo and in vitro. Glycoproteins with blood group A specificity were observed by SDS-PAGE and Western blotting procedures in the membrane fraction of PC-1 cells, with a major component of molecular mass of approximately 120 kd. Similar migration patterns were observed in the primary induced PC and in subcutaneous and intrapancreatic transplants of PC-1 cells. Membrane preparations from cell lines derived from two primary pancreatic cancers from patients of blood group A and from human pancreatic cell lines, CD11 and CD18, showed a major A reactive component with a molecular mass similar to that found in the hamster PC cells. These findings suggest that: (i) both the hamster and human PC cells in vitro produce glycoproteins with blood group A specificity of similar molecular masses; (ii) differences exist in the structure of the glycoprotein immunoreactive with the anti-A antigen between the normal and cancerous cells; and (iii) differences exist in the molecular mass of the anti-A reactive substance between hamsters and human PC cells and between tissues in vivo and in vitro.

Comparative studies on expression of tumor-associated antigens in human and induced pancreatic cancer in Syrian hamsters.

The expression of blood-group-related antigens (BGRAs) in experimental primary pancreatic cancer induced by N-nitrosobis(2-oxopropyl)amine (BOP) treatment of Syrian hamsters and homologous subcutaneous transplants of this primary cancer in the cell line, PC-1, established from the primary cancer and intrapancreatic transplanted PC-1 cells were studied by histochemical and biochemical methods. Human primary pancreatic cancer; the human pancreatic cancer cell line, HPAF; and its subclones, CD11 and CD18, also were studied on a comparative basis. Histochemical analysis of BGRAs demonstrated that A, B, H, Leb, Lex, Ley, and T antigen were expressed both in vivo and in vitro in hamster and human materials in similar patterns. However, Lea, CA 19-9 and sialylated Tn antigens were not found in hamster-derived tissues. SDS-PAGE and Western blotting procedures using anti-A antigen revealed similar major bands in the membrane fractions of both human and hamster pancreatic cells between 97 and 200 kdalton. Among other human pancreatic cancer-associated antigens, TAG-72, CA 125, and 17-1A were detected immuno-histochemically in the hamster tumors both in vivo and in vitro, in a pattern similar to that seen in human pancreatic cancer. Tumor antigen DU-PAN-2, associated with human pancreatic cancer, was found infrequently in hamster pancreatic cancer specimens. These results indicate that the experimental hamster pancreatic cancer model provides a unique tool for investigating antigenicity of pancreatic cancer, particularly in relation to diagnosis and therapy.